The directions say not to open the teabag but to punch holes in it with a toothpick. Does that mean I should leave the teabag in the cellophane?
No. You should remove the teabag from the cellophane, but please do not open the teabag itself. Well, you could if you really wanted to, but then the tank water would be dirty enough that the baby Triops would be hidden from view. Poking the holes in the teabag allows extra nutrient to release without muddying the water. That is the trick: feed the Triops but keep the water clear enough so that you can marvel at the babies as they hatch.